Filtering assemblies for cleaning an air or gas stream carrying particulate matter typically include filter elements disposed within a housing. The particulate matter-carrying stream is passed through the housing so the particulates are captured and retained by the filter elements.
Cylindrical filter elements are commonly used in air filter assemblies to process dust particles from an air stream. In a standard design, an air filter assembly has a clean air chamber and a dirty air chamber. The two chambers are separated by a partition or wall, such as one made from sheet metal; such a wall is commonly referred to as a tube sheet. The tube sheet has a number of openings from which cylindrical filters are aligned. The filters suspend downwardly with or without an angle from the tube sheet openings into the dirty air chamber. Particulate-laden air is introduced into the dirty air chamber, and the particulates collect onto the filter. The filtered air passes through the filters to the interior of the filters, and upwardly out through the openings in the tube sheet into the clean air chamber. From the clean air chamber, the cleaned air is exhausted into the environment, or recirculated for further use.
Any particular filter assembly can have multiple filter constructions. The filter elements of a filter construction are supported by a frame or yoke attached to the tube sheet. The end of the filter is sealed with an access cover which is secured to the end of the yoke opposite the tube sheet.
It is periodically necessary to access the filter elements to determine whether maintenance or replacement of the filter elements is necessary. The replacement of used filter elements is a process that requires opening the access cover, removal of the filter elements, placement of different filter elements on the yoke, and replacement of the cover in such a way to ensure the proper amount of tightening of the cover onto the filter element(s). There are typically many covers on a housing corresponding with the number of filter elements in the filter assembly and the above process must be performed for each cover.
It is well-known in the art to use cylindrical filter element having a round sidewall. More recently, cylindrical filter elements having oval sidewalls have been introduced. The filter assemblies utilizing such oval filter elements are typically supplied with access covers conforming to the oval shape of the filter elements. Such a structure is described in U.S. Pat. No. 6,368,388.
For example, these access covers include a plate or sealing member, a catch and a tightening member. The plate is shaped and has a contoured surface capable of sealingly covering the end of an oval filter element. Accordingly, these plates include a first circumferential, outwardly convex, oval-shaped center portion or guide that fits within the end of an oval filter element. A circumferential, inwardly concave receiving surface is located radially outwardly of the convex guide. The receiving surface has a width sized to receive and seal the oval end cap of the oval filter element. A gasket for sealing the end cap may be included within the receiving surface. A second circumferential, outwardly convex, oval-shaped guide is separated from the first guide by the receiver, and ensures the end cap of the filter element is secure within the receiver. The plate also is shaped to sealingly interact with the front sheet of the filter assembly.
One problem associated with the filter assemblies utilizing oval filters is the filter assemblies are manufactured, as suggested above, to accept only oval filter elements. This is a problem because oval filter elements may not be readily available. Thus, it would be desirable to be able to adapt existing filter assemblies manufactured to accept only oval filters to accept filter elements of varying shapes, including round and oval.
The present invention is provided to solve the problems discussed above and other problems. A full discussion of the features and advantages of the present invention is deferred to the following detailed description, which proceeds with reference to the accompanying drawings.